1. Field of Invention
The invention hereinafter described and claiemd pertains to pallets upon which cargo is loaded for air transportation, and more particularly, to the manner and materials of their construction.
2. Prior Art
The prior art air cargo pallet is generally described in U.S. Specification MIL-P-27443. Basically, the prior art pallet is a piece of balsa wood, to which two aluminum sheets are laminated. The pallet of this construction weighs approximately three hundred to over a thousand pounds (depending on size) and has a service life, typically, of twelve to eighteen months. This limited service life is due to the fact that cargo, which is dropped onto the top surface of the pallet, and the forklift tines which impact the bottom surface of the pallet, cause deformation of the aluminum sheets. This deformation, in turn, causes a delamination of the bond between the aluminum sheet and the balsa wood core immediately in the area of the deformation. Then, as the pallet is used, and is subjected to lateral and other varying stresses, and, as it travels via conveyor belt and undergoes a rippling effect when it transfers from one conveyor belt to another conveyor belt at a slightly, or in some occasions, greatly, differing elevations, the delamination begins to spread.
If unnoticed, the delamination will progress to a point where there is a substantial risk of total failure of the pallet, wherein one or the other of the aluminum sheets will completely separate from the balsa wood center. As can be imagined, if that was to occuring flight, a seriously dangerous condition might result, endangering the aircraft and crew. Therefore, because it is quite difficult to constantly monitor the amount of deformation and delamination of the prior art pallet, they are regularly scrapped after twelve to eighteen months in use. As these pallets can cost at least $900 or $1,000 each, there is a substantial cost associated with the continual replacement of the prior art pallets.
There is, therefore, a need in the art for a cargo pallet with greater service life potential, such that the overall cost of use of the pallet can be reduced. However, as with any apparatus used in air transport, the divergent goals of light weight and strength are desired. Accordingly, any new cargo pallet must exhibit the light weight and strength obtained in the prior art blasa wood pallet.